package com.atguigu.rabbitmq.four;

import com.atguigu.rabbitmq.utils.RabbitMqUtils;
import com.rabbitmq.client.Channel;
import com.rabbitmq.client.ConfirmCallback;

import java.nio.charset.StandardCharsets;
import java.util.UUID;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.ConcurrentSkipListMap;

/**
 * 发布确认模式
 * 比较使用的时间，确认哪种确认方式是最好的
 * 1.单个确认
 * 2.批量确认
 * 3.异步批量确认
 *
 * @author 连志阳
 * @since 2022/2/8
 */
public class ConfirmMessage {
    //批量发消息的个数
    public static final int MESSAGE_COUNT = 1000;
    
    public static void main(String[] args) throws Exception {
        //1.单个确认
        //publishMessageIndividually();//发布1000个单独确认消息，耗时555ms
        //2.批量确认
        //publishMessageBatch();//发布1000个批量确认消息，耗时88ms
        //3.异步批量确认
        publishMessageAsync();//发布1000个异步发布确认消息，耗时30ms
        //添加ConcurrentSkipListMap后，发布1000个异步发布确认消息，耗时31ms
    }
    
    /**
     * 单个确认
     */
    public static void publishMessageIndividually() throws Exception {
        Channel channel = RabbitMqUtils.getChannel();
        //队列声明
        String queueName = UUID.randomUUID().toString();
        channel.queueDeclare(queueName, true, false, false, null);
        //开启发布确认
        channel.confirmSelect();
        //开始时间
        long begin = System.currentTimeMillis();
        //批量发消息
        for (int i = 0; i < MESSAGE_COUNT; i++) {
            String message = i + "";
            channel.basicPublish("", queueName, null, message.getBytes(StandardCharsets.UTF_8));
            boolean flag = channel.waitForConfirms();
            if (flag) {
                System.out.println("消息发送成功");
            }
        }
        //结束时间
        long end = System.currentTimeMillis();
        System.out.println("发布" + MESSAGE_COUNT + "个单独确认消息，耗时" + (end - begin) + "ms");
    }
    
    /**
     * 批量发布确认
     */
    public static void publishMessageBatch() throws Exception {
        Channel channel = RabbitMqUtils.getChannel();
        //队列声明
        String queueName = UUID.randomUUID().toString();
        channel.queueDeclare(queueName, true, false, false, null);
        //开启发布确认
        channel.confirmSelect();
        //开始时间
        long begin = System.currentTimeMillis();
        
        //批量确认消息大小
        int batchSize = 100;
        for (int i = 0; i < MESSAGE_COUNT; i++) {
            String message = i + "";
            channel.basicPublish("", queueName, null, message.getBytes(StandardCharsets.UTF_8));
            //判断达到100条消息的时候批量确认一次
            if (i % batchSize == 0) {
                //发布确认
                channel.waitForConfirms();
            }
        }
        
        //结束时间
        long end = System.currentTimeMillis();
        System.out.println("发布" + MESSAGE_COUNT + "个批量确认消息，耗时" + (end - begin) + "ms");
    }
    
    /**
     * 异步发布确认
     */
    public static void publishMessageAsync() throws Exception {
        Channel channel = RabbitMqUtils.getChannel();
        //队列声明
        String queueName = UUID.randomUUID().toString();
        channel.queueDeclare(queueName, true, false, false, null);
        //开启发布确认
        channel.confirmSelect();
        
        /*
        线程安全有序的一个哈希表，适用于高并发的情况下
        1.轻松的将序号于消息进行关联
        2.轻松批量删除条目，只要给到序号
        3.支持高并发（多线程）
         */
        ConcurrentSkipListMap<Long, String> outstandingConfirms =
            new ConcurrentSkipListMap<>();
        
        //消息确认成功 回调函数
        ConfirmCallback ackCallback = (deliveryTag, multiple) -> {
            //2：删除已确认的消息，剩下的就是未确认的消息
            if (multiple) {
                ConcurrentNavigableMap<Long, String> confirmed =
                    outstandingConfirms.headMap(deliveryTag);
                confirmed.clear();
            } else {
                outstandingConfirms.remove(deliveryTag);
            }
            
            System.out.println("确认的消息：" + deliveryTag);
        };
        //消息确认失败 回调函数
        /*
        1.消息的标记
        2.是否为批量确认
         */
        ConfirmCallback nackCallback = (deliveryTag, multiple) -> {
            //3：打印未确认的消息都有哪些
            String message = outstandingConfirms.get(deliveryTag);
            System.out.println("未确认的消息是：" + message + "····未确认的消息tag：" + deliveryTag);
        };
        //消息监听器，监听哪些消息成功，监听哪些消息失败
        /*
        1.监听哪些消息成功
        2.监听哪些消息失败
        异步通知
         */
        channel.addConfirmListener(ackCallback, nackCallback);
        
        //开始时间
        long begin = System.currentTimeMillis();
        //批量发送消息
        for (int i = 0; i < MESSAGE_COUNT; i++) {
            String message = "消息" + i;
            channel.basicPublish("", queueName, null, message.getBytes(StandardCharsets.UTF_8));
            //1：此处记录下所有要发送的消息总和
            outstandingConfirms.put(channel.getNextPublishSeqNo(), message);
        }
        
        //结束时间
        long end = System.currentTimeMillis();
        System.out.println("发布" + MESSAGE_COUNT + "个异步发布确认消息，耗时" + (end - begin) + "ms");
    }
}
